PsychoDave Posted March 16, 2017 Share Posted March 16, 2017 Hello everyone, I've got a quick question... My Colecovision doesn't turn on, that is to say when I flip the power switch I get no picture on my TV. I've replaced the power switch already with a Radio Shack DPDT Rocker - 275 691. I've checked continuity with my meter as well as voltage. When I check the PSU with the system in "Off" I get all the correct voltages 12v, 5v and -5v but when I turn the switch on the 12v rail drops to 6v. I checked voltages on the back of the plug receptacle and at the board where the switch is connected. A 6v drop seems to be a bit excessive... So, where do I go from here? Do I crack open the PSU or could there be an issue on the board? Any help would be greatly appreciated. Dave Quote Link to comment Share on other sites More sharing options...
PsychoDave Posted March 17, 2017 Author Share Posted March 17, 2017 Cant find the edit button, sick of trying... If someone can edit the 1st post to include this, awesome. If not...no worries I just wanted to add that ch 3 and 4 on my tv are static...always When I power up the Coleco there is no image, no black screen just static. I don't know if that helps... Also, I'm thinking my problem could be a capacitor in the brick... Dave Quote Link to comment Share on other sites More sharing options...
cdn2a Posted March 17, 2017 Share Posted March 17, 2017 It could be your powersupply or it could be something else dragging down your 12v line. A crude method would be, to turn it on wait for a few seconds then touch the video ram chips and see if one is hotter than the others. you can then start disconnecting chips from the 12v rail till your voltage stabilizes. Quote Link to comment Share on other sites More sharing options...
thecrypticodor Posted March 18, 2017 Share Posted March 18, 2017 (edited) I'd bet it's the power supply. All the CV powers supplies that I've worked on that had it's original capacitors were always out of spec. I've resurrected quite a few CV power supplies by simply just recapping them. Edited March 18, 2017 by thecrypticodor 1 Quote Link to comment Share on other sites More sharing options...
coleconut Posted March 19, 2017 Share Posted March 19, 2017 I'd bet it's the power supply. All the CV powers supplies that I've worked on that had it's original capacitors were always out of spec. I've resurrected quite a few CV power supplies by simply just recapping them. CV caps.png This is good to know, but what the challenge for me is the best way to open the darn things then put them back together so they dont look like some night-before-due school project. Quote Link to comment Share on other sites More sharing options...
thecrypticodor Posted March 19, 2017 Share Posted March 19, 2017 This is good to know, but what the challenge for me is the best way to open the darn things then put them back together so they dont look like some night-before-due school project. Sometimes you can get lucky and pop the plastic apart enough to start prying by applying pressure around the seem. I’ve also done it by sticking a flat blade screwdriver in between the slot for the strain relief and gently prying. It's more likely than not you're gonna do some damage to the housing, but what’s more important it working or looking pretty. Quote Link to comment Share on other sites More sharing options...
PsychoDave Posted March 19, 2017 Author Share Posted March 19, 2017 Apparently Radio Shack is going belly up again, unless they can find funding. As a result all sales are final and no new shipments are coming in. After sifting through the component drawers I could only find 4 of the capacitors but they were axial, not radial. I've ordered all the capacitors from amazon and should have them on Tuesday. Now I just need to get a dremel so I can open up the housing. What have people done to close the housing back up after cutting it open? Plastic cement? Quote Link to comment Share on other sites More sharing options...
PsychoDave Posted March 22, 2017 Author Share Posted March 22, 2017 My parts arrived today and I've opened up the PSU case. I didn't have a chance to work on it any more than that. Here are a few pictures of the guts and I'll post more as I replace the capacitors, hopefully it will help someone down the road. Dave Quote Link to comment Share on other sites More sharing options...
Jess Ragan Posted March 22, 2017 Share Posted March 22, 2017 Do they have a viable alternative to these damned things yet? The CV I got didn't come with a power supply, and I'd prefer to avoid the standard model if at all possible. Just no sense in a five pound brick dangling from the wall. Quote Link to comment Share on other sites More sharing options...
omf Posted March 22, 2017 Share Posted March 22, 2017 I had a dead colecovision power supply once, I had to throw it away. i cracked it open to look into fixing it and it had grey epoxy over everything. it was not a thin coating, it was full to the brim. it would have taken many weeks to get all that shit off which i was not prepared to do. i was a bit pissed to be honest, why do that!!!!!! Quote Link to comment Share on other sites More sharing options...
PsychoDave Posted March 23, 2017 Author Share Posted March 23, 2017 Well, I've finished swapping out all the capacitors in the PSU. After temporarily covering it back up and plugging it in, I've got all the correct voltages. 12 VDC, -5 VDC and 5 VDC with no load. However, as soon as I turn the coleco on the 12v rail drops to 6v again. So, either my PSU is just bad or something else is wrong... Any Ideas? I guess ill check the video ram as suggested by cdn2a Here is an album of pictures I took while swapping out the caps. http://smg.photobucket.com/user/beaverbandit/library/Colecovision%20PSU%20Capacitor%20swap Sample pic: Quote Link to comment Share on other sites More sharing options...
rassafrassa Posted October 30, 2017 Share Posted October 30, 2017 Did you figure out the problem? I have the exact same problem on 2 different systems- this is the only reference I can find online Quote Link to comment Share on other sites More sharing options...
imstarryeyed Posted October 31, 2017 Share Posted October 31, 2017 I just got some chips in and I am experimenting with converting an XBOX 360 green brick power supply to colecovision. I too hate the power supplies and do not wish to use an arcade power supply if I can avoid it. Quote Link to comment Share on other sites More sharing options...
shabazz18 Posted November 1, 2017 Share Posted November 1, 2017 (edited) Your 12v regulator is bad. Mine had the exact same problem. I just installed the kit from console 5 since it has everything. https://console5.com/store/colecovision-console-power-supply-cap-kit.html Edited November 1, 2017 by shabazz18 1 Quote Link to comment Share on other sites More sharing options...
shabazz18 Posted November 1, 2017 Share Posted November 1, 2017 Did you figure out the problem? I have the exact same problem on 2 different systems- this is the only reference I can find online Bad 12v regulator Sent from my Pixel 2 using Tapatalk 1 Quote Link to comment Share on other sites More sharing options...
towmater Posted November 1, 2017 Share Posted November 1, 2017 Suggest doing a 5V only mod, possibly cheaper than resurrecting the beast. Quote Link to comment Share on other sites More sharing options...
shabazz18 Posted November 1, 2017 Share Posted November 1, 2017 Suggest doing a 5V only mod, possibly cheaper than resurrecting the beast.That won't help with a 12v-6v voltage drop under load. Nothing wrong with the console, it's the 12v regulator in the PSU. Sent from my Pixel 2 using Tapatalk 1 Quote Link to comment Share on other sites More sharing options...
towmater Posted November 1, 2017 Share Posted November 1, 2017 (edited) I'd think it might help, as you'd be bypassing anything in the console that uses anything other than 5V? I guess it is a matter of how much you want to spend, though Console 5's five-volt mod kit is under $15. At that point, an iPad charger could act as your PSU, offering more current than the old brick. Edited November 1, 2017 by towmater Quote Link to comment Share on other sites More sharing options...
shabazz18 Posted November 1, 2017 Share Posted November 1, 2017 (edited) I'd think it might help, as you'd be bypassing anything in the console that uses anything other than 5V? I guess it is a matter of how much you want to spend, though Console 5's five-volt mod kit is under $15. At that point, an iPad charger could act as your PSU, offering more current than the old brick. Fair enough, just seems like a very convoluted solution to a 3 solder point problem. Sent from my Pixel 2 using Tapatalk Edited November 1, 2017 by shabazz18 Quote Link to comment Share on other sites More sharing options...
Bmack36 Posted November 1, 2017 Share Posted November 1, 2017 (edited) The 5V mod is not actually a full 5V mod. It does reduce the VRAM to only using 5V which is helpful, but the system still needs 12V for the video output. The only current way to only use only 5V is to use the F18a. Edited November 1, 2017 by Bmack36 1 Quote Link to comment Share on other sites More sharing options...
rassafrassa Posted November 1, 2017 Share Posted November 1, 2017 thank you! ebay 'tested working' strikes again Quote Link to comment Share on other sites More sharing options...
towmater Posted November 1, 2017 Share Posted November 1, 2017 Though, correct me if I am incorrect, only if one is using the RF modulator instead of composite. Is anyone still doing that? Quote Link to comment Share on other sites More sharing options...
shabazz18 Posted November 1, 2017 Share Posted November 1, 2017 Though, correct me if I am incorrect, only if one is using the RF modulator instead of composite. Is anyone still doing that? Me. Sent from my Pixel 2 using Tapatalk Quote Link to comment Share on other sites More sharing options...
towmater Posted November 1, 2017 Share Posted November 1, 2017 You are truly retro sir, I salute you. Quote Link to comment Share on other sites More sharing options...
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